1. Field
The present disclosure relates generally to voltage regulation and, in particular, to a method and apparatus for managing current. Still, more particularly, the present disclosure relates to a method and apparatus for managing a current obtained from an energy harvesting device.
2. Background
To support the world's growing consumer market, there is an unprecedented need to track the flow of products as they are manufactured in one country, transported across the world, and then consumed in another country. Manufacturers, distributors, and retailers have relied on bar code labels to track their products and manage their inventories. While barcode labels have many advantages, including low cost, they also have several disadvantages. For example, the bar code label of the product may be in a specific orientation and proximity to the reader when the bar code label is correctly read. Moreover, printed bar code labels are limited by the amount of data that they can store.
Radio frequency identification (RFID) provides the ability to store and retrieve significant amounts of information about a product. Radio frequency identification tags are generally grouped into three categories: passive, active, and semi-passive. Passive tags do not have an internal power source. Instead, they rely on inducing an electrical current in the tag's antenna from the reader's incoming RF signal. Semi-passive tags are similar to active tags in that they have their own power source, but the battery only powers the micro-chip and does not broadcast a signal. Active tags use a power source, such as a battery, to power the micro-chip and broadcast the signal to the reader.
Batteries used to power active tags may run out of power and need to be replaced. Replacing the battery may be difficult and costly. Furthermore, in an environment where there are many tags, replacing all of the tags or batteries on the tags may be time consuming and costly.
Therefore, it would be advantageous to have a method and apparatus that takes into account one or more of the issues discussed above, as well as possibly other issues.